(video credits: Dr John Campbell) Batch-dependent safety of the BNT162b2 mRNA COVID-19 vaccinehttps://onlinelibrary.wiley.co....m/doi/10.1111/eci.13 of the suspected adverse reactions occurred in 4.2% of the vaccine batchesNumbers of suspected adverse events (SAEs),after BNT612b2 mRNA vaccination in Denmark.27 December 2020–11 January 2022, (population 5.8 million)(According to the number of doses per vaccine batch) Each dot represents a single vaccine batch. By 11 November 2022 (European area)701 million doses of Pfizer given971,021 reports of suspected adverse effects (SAEs)Clinical data on individual vaccine batch levels have not been reported(batch-dependent variation in the clinical efficacy and safety of authorized vaccines would appear to be highly unlikely)We therefore examined rates of SAEs between different BNT162b2 vaccine batches administered in DenmarkData on all SAE cases, Danish Medical Agency (DKMA)SAE seriousness was classified as non-serious, serious (hospitalization or prolongation of existing hospitalization, life-threatening illness, permanent disability or congenital malformation) or SAE-related d****Anonymized dataSAEs were counted on a batch level by linking individual SAEs to the batch label(s) of BNT162b dose(s)10,793,766 doses administered4,026,575 persons52 different BNT162b2 vaccine batches(2,340–814,320 doses per batch)43,496 SAEs were registered in 13,635 persons61,847 batch-identifiable SAEs,of which 14,509 (23.5%) were classified as severe,579 (0.9%) were SAE-related d*****UnexpectedlyRates of SAEs per 1000 doses varied considerably between vaccine batchesFrom 1 SAE per 20 doses given to I in many thousands to zeroVariabilitiesVaccine manufacturingStorageTransportationClinical handling and controlAdministration technique